Grinding machine



2, 1934- L. w. JOHNSON ET AL GRINDING MACHINE 5 Sheets-Sheet 1 Filed March 21, 1929 Jan. 2, 1934.

L. W. JOHNSON El AL GRINDING MACHINE Filed March 21, 1929 5 Sheets-Sheet 2 Jan, 2 1934. L. w. JOHNSON ET AL 1,941,478

GRINDING MACHINE Filed March 21, 1929 5 Sheets-Sheet 3 lvzzard fife/072725072- 772%0/2 Ffldf i'frawa I I Jana 1934- 1.. w. JOHNSON El AL 1,941,473

GRINDING MACHINE Filed March 21, 1929 5 Sheets-Sheet 4 llllllillllllllillllll.

Jan. 2, 1934. L. w. JOHNSON ET AL,

GRINDING MACHINE;

5 Sheets-Sheet 5 Filed March 21, 1929 Patented Jan. 2, 1934 UNITED STATES GRINDING MACHINE Leonard W. Johnson and Wilton F. Hoag,

Batavia, Il1., assignors to Johnson Manufacturing Company, Batavia, 111., a corporation of Illinois Application March '21, 1929. Serial No. 348,931

34 Claims.

Our invention relates to grinding machines for grinding reamer blades of various types having their cutting edges formed on the outer periphery of the blades and extending longitudinally of a shank or holding device, such as par ticularly the reamer blades of the type shown in Patent No. 1,479,079. of .January 1, 1924.

The primary object of our invention is the provision of a grinding machine which grinds the blades of the reamer .with relief portions at each end of the reamer blades, so that the main cutting portion of the reamer enters the bearing opening in the proper manner and leaves the bearing opening properly without scoring or destroying the bearing at the end.

The central portion .of the blades perform the cutting operation and it is necessary in order that the reamer give proper results, that the blades of the reamer be ground exactly alike or in such form that the blades form a. perfect cylinder so that the bearing opening is true and properly formed.

Another and further object of our invention is the provision of a grinding machine in which the grinding wheel is brought into contact with the surface forming the cutting edge of the blades of the reamer in a longitudinal direction rather than in a transverse direction,.which has been the common practice in the grinding of blades heretofore. When the grindingoperation is performed transversely to the edges of the blades, the edges are left somewhat ragged with serrations formed extending at right angles to the center line of the blades, thereby preventing the blades from making a smooth cut in the bearing. I

Another and further object of our invention is the provision of a grinding machine which performs the function of grinding the reamer blades so that the cutting edge is horizontal to the longitudinal axis of the blades during the initial manufacture thereof, but also to the proper grinding of the relief portions of the blades when the blades are originallymanufactured, and in addition to these operations the machine performs the operation of resharpening the blades after they have become dull, and retains the proper contour of the blades with a minimum of settings and changing of the machine, so that an ordinary mechanic can resharpen these blades.

It will be understood that automobile repair shops and garages generally doing repair work on automobiles, require machines which .will' perform exceedingly accurate work, and what this character of work.

was considered good practice in tolerances a few years ago, is now discarded and the doing of the ordinary repair job on an automobile requires an exactness that is comparable only to that in the manufacture of precision instruments. In the practice of grinding reamer blades heretofore, the grinding has been most successfully accomplished upon a machine having a saucer shaped wheel with the grinding surface at the side .of the wheel at the outer periphery thereof, the cutting edge of the grinding wheel running across the blade of the reamer in a transverse direction as above described. The operation has been accomplished upon a grinding machine having a holder mounted upon a table moving in a straight longitudinal plane and under the con- .trol of the operator. In a large measure the proper grinding of a blade was dependent upon the skill of the operator and the proper sharpening of the bladeshas not been possible of accomplishment heretofore except by manufacturers of reamer blades having grinder operators in their employ who have had long experience in The grinding of the relief portions of the blades has been accomplished by .a table having a portion arranged so that it would move on a pivotal axis in a horizontal direction, but the acquiring of the proper taper on the blades has been a matter of .the skill of the operator and it has not been possible .to grind two blades exactly alike so far as the taper is concerned.

In our improved machine the control of the grinding table is automatic and out of the hands of the operatorexcept the reciprocating movement of the grinding table and as the table is reciprocated the grinding table is automatically tilted so that regardless of how often the table maybe reciprocated under the grinding wheel, thecutting portion formed on the blades is precisely the same in each instance.

Another and further object'of our invention is the provision of a grinding machine which is easily adjustable for Various kinds, classes, and

sizes of reamer blades, .50 that it can be used to perform a-multiplicity'of operations with a minimum of adjustment so that any ordinary mechanic can operate the machine.

Another and further object of ourinvention is the provision of .a machine which is adapted to generate a stream line curve asapplied to the outercontour of various forms of reamer blades.

These and'other objects will be more fully'and better understoodbyreference to the accompanyingsheets. of drawings, in which- Figure 1 is a fragmentary end elevational View of a grinding machine embodying our invention;

Figure 2 is a fragmentary front side elevational view of a grinding machine shown in Figure 1;

Figure 3 is a fragmentary rear side elevation of a grinding machine embodying our invention;

Figure 4 is a vertical sectional View on lines 4-4 of Figure 3;

Figure 5 is a top plan view of the mounting casting for the first and second cams;

Figure 6 is a side elevational View of the casting illustrated in Figure 5;

Figure 7 is a vertical sectional view on lines '7'? of Figure 3;

Figure 8 is a horizontal sectional view on lines 88 of Figure 3; and

Figure 9 is an elevational view illustrating the contour lines of the cutting blades mounted upon a reamer spindle.

Referring now specifically to the drawings, a frame 10 is shown having a vertically extending U-shaped member 12 mounted thereon within which a grinding shaft 13 is mounted having a pulley 14 thereon around which the driving belt for the grinding shaft extends. A grinding wheel 15 is mounted on the outer end of the grinding shaft 13 and is adapted to contact with the outer surface of the blades of the reamer for purposes of grinding the reamer blades to form the cutting edges thereon. Mounted upon the frame 10 is a table 16 adapted to reciprocate in a horizontal direction in a straight line on the frame 10, as is common with machines of this character Suitable hand mechanism (not shown) is used for reciprocating the table 16 on the frame 10, thereby moving the reamer blades under the grinding wheel 15.

Supporting the table 16 is a cross slide 1'7 which in turn is supported upon a guideway 18 mounted upon the frame 10. A hand wheel 19 is provided for moving the table 16 in a transverse direction along the guideway 18 in order to properly center the reamer blades with respect to the grinding wheel 15. A hand wheel 20 is shown which, by means of suitable mechanism, also in common use on machines of this type, is adapted to raise and lower the cross slide 17 and the operating parts connected thereto, including the table 16.

A tilting table composed of an upper member 21 and a lower member 22 is provided, the lower member 22 having a bracket 23 secured thereto by bolts 24, 24 with a lower bracket 25 being provided which is secured to the table 16 by bolts 26, 26. The upper bracket 23 has an upper bearing member 27 mounted therein which engages in the bracket 25, so that the upper table is tiltedly mounted upon the lower table 16, and pivots about the bearing member 27 as a center. Mounted at one end of the upper member 21 is a lug 28 which projects downward and has a member 29 extending therethrough, the member 29 being threaded on its internal end in engagement with the bracket 30 which is fixed to the lower member 22 of the table. The purpose of this member 29 is to move the upper member 21 relative to the lower member 22 for the purpose of bringing the tool holders into proper relationship with the grinding wheel as hereinafter described.

A locking member 31 is provided which is operable by a handle 32 to lock the two members 21 and 22 into fixed engagement with each other when desired by the operator. Secured to the member 21 and projecting upwardly therefrom is a pair of adjustable brackets 33 and 34,

the bracket 33 having a fixed pin mounted therein adapted to engage in the center hole of the reamer body 36, with a spring-pressed center member 37 being provided in the bracket 34 to engage in the center hole of the reamer body at its opposite end, thereby holding the reamer between the brackets 33 and 34. The pin 37 is capable of being moved outwardly in the bracket 34 so that the reamer body can be placed into position on the pin members 35 and 37 and removed therefrom, at the same time being rotatable on these pin members by the operator. As shown in Figure 2, the reamer body has a threaded nut 38 mounted thereon with a spring 39 and a bushing 40 adapted to engage the ends of the blades 41. A threaded bushing 42 is shown over the opposite end of the reamer body 36, so that the blades 41 areheld in position alongside of the reamer body or stock in the same manner as when the reamer is being used for the purpose of reaming out bearings.

For the purpose of securing the proper adjustment of the member 21, a centering device is provided which consists of an arm 43 pivotally mounted upon ears 44 integrally formed with the bracket 25 and projecting outward therefrom. A link 45 is secured to the arm 43 by a pin 46, the link 45 having a V-shaped end 47 which is adapted to engage on the upper outer edge of the member 21 thereby insuring the positioning of the arm 43 in a vertical line. At the upper end of the arm 43 is a pivotally mounted centering member 48 having a hardened point member 49 mounted on the inner end thereof, this member 49 being cone-shaped on its free end and is adapted to be received into the center hole of the grinding shaft 13. A link 50 is provided which is joined to the arm 43 by a pin 51 which also extends through the centering member 48. The link 50 has an extension member 52 pivotally secured thereto and the member 52 has a gauge member 53 mounted thereon by rivets or in any other approved manner. The arm 43 and gauge member 53 are for the purpose of determining the proper position of the reamer with respect to the grinding wheel 15 during the grinding operation.

Secured to the member 17 is a spacing block 54 to the side of which is secured a frame member 55, the spacing block 54 and frame member 55 being held in position to the member 17 by means of bolts 56. The frame member 55 has a circular opening 57 therein with an elongated opening 58 at the side of the circular opening 57, with a rectangular opening 59 adjacent the lower side of the member 55. A mounting casting designated as a whole as 60, is shown, which comprises a circular portion 61 having an annular oilset portion 62 with a further annular stepped portion 63 which is adapted to fit into ear 68 which project through the opening 57 in the casting 55 and which have a pair of oppoistely disposed set screws 69 and 70 in threaded engagement therewith, these set screws having cone-shaped points. An opening 71 is provided in the casting for the purpose of receiving A ring is provided with a portion of a cam, as will be more fully described hereinafter. a

The casting 60 has a portion 72 integrally formed therewith which is connected to the portion 61 by a web portion 73, the portion 72 having an upper lip portion 74 and a lower lip portion 75 formed thereon, within which an upper cone-pointed set screw .76 is mounted and a lower cone-pointed set screw 77 is positioned for purposes hereinafter described. A vertically extending opening 78 is formed in the member 72 within which a holding block 79 is mounted. The holding block 79 has a head portion 80 formed thereon with a lip portion 81 projecting outwardly therefrom, the head portion 80 having side faces 82, 82 formed thereon against which one of the cams hereinafter described is adapted to seat. The head 80 also has a transversely extending channel 83 formed therein for the purpose of receiving a guide bar 84 which is held in position by a screw 85, which extends through the head portion 80,

the head of the screw 85 being countersunk so as not to interfere with the engagement of the holding block 79 with the holding casting 72.

The holding block 79 has an opening 86 formed therein within which an adjusting block 87 is positioned. A plate 88 is provided which fits against the outer end of the member 79 and has a pair of screws 89, 89 extending therethrough in engagement with the member 87. A second threaded member 90 is provided which extends through the plate 88 and is in threaded engagement with the member 87 by means of which longitudinal movement of the member 87 is effected, this arrangement being for the purpose of securing proper adjustment and holding of one of the cam members described hereinafter.

Integrally formed with the casting 55 is an upper lug 91 and a lower lug 92, the lug 91 having a set screw 93 mounted therein, the lug 92 having a threaded bolt 94 mounted therein and a fixed nut 95 mounted thereon, the upper screw 93 and lower bolt 94 being in engagement with a lug 96 which is secured to the mounting casting 60 by screws, or in any approved manner, at the rear side of the casting 60 and provides means by which the casting 60 is rotated about its center in the opening 57 in the casting 55.

The casting 60 has a vertically extending channel 97 formed therein within which a cam member 98 is seated, the cam member 98 having an outwardly projecting lug 99 formed thereon with seats formed in each side thereof within which the cone-shaped points of the set screws 69 and 70 are adapted to engage, these screws providing means for the vertical adjustment of the cam 98. The cam member 98 has an upper bearing surface 100, the cam member 98 being so adjusted that this surface is parallel to the travel of the table 16 and remains in this position throughout the operation of the device. The set screw 93 and bolt 94 are provided by means of which the cam 98 is adjusted to a position so the bearing surface 100 is parallel with the travel of the said table 16.

A second cam 101 is provided which extends forward past the head portion 80 on the holding member 79 and rests upon the lip portion"81 of the head 80 and bears against the shoulders 82 of the head portion 80 of the holding member 79. A longitudinally extending channel 102 is formed in the cam 101 within which the guide bar 84 is seated, thereby holding the cam member firmly in position with respect to the holding member 79. A threaded member 103 is provided which is in threaded engagement with the member 87 and has a hand nut 104 on the outer end thereof with a threaded filler member 105 being inserted in the outer end of the cam member 101 with a shoulder portion 106 being formed on the member 103 so that rotation of the screw 103 results in longitudinal movement of the cam 101.

A casting 107 is provided having .a circular portion 108 which is adapted to fit against the :side of the casting 55, with an opening 109 being provided through the lower section of the casting 107 through which a bolt 110 extends. Mounted in the opening "59 in the lower side of the casting 55 is a sliding block 111, the said block being threaded at its outer end and has a nut 11 2 thereon with a washer 113 being interposed between the nut and the face of the casting member 55. The bolt has a head 114 integrally formed therewith and a nut 115 on the opposite end thereof. The bolt head 114 has a cone .surface 116 which is adapted to co-act with a split bushing comprising an upper section 117 and a .lower section .118, this bushing having angular-- ly disposed surfaces at its inner end adapted to engage against a bushing 119 so that when the bolt 110 is tightened the .sections 117 and 118 of the split bushing expand, thereby holding the casting 107 and all attached parts against rotation. This is accomplished by means of friction between the outer surfaces of the bushing sections 117 and 118 and the surface of the hole through the sliding block :111 within which the bushing sections .117 and .118 .and the bushing 119 are mounted. The bolt 110 .and the bushings are so made as to provide a close sliding fit before being tightened by the bolt 110.

The casting 107 has a vertically extending portion 120 formed integrally therewith, with an opening 121 therein, with an upper .lug 122 .and a lower lug 123 formed integrally with the portion 120, within which a .pair of oppositely disposed cone-pointed 'set screws 124 and 125 are disposed respectively. The portion 120 of the casting 107 has a channel portion 126 formed therein within which the rib portion 127 of a 120 cam 128 is seated. The rib portion v127 has .an outwardly extending lug 129 formed therein having :seats formed therein adapted to receive the cone-pointed screws 124 and 125 respectively, by means of which vertical adjustment of the cam 128 is accomplished.

Secured to the lower section '22 of the tilting table and extending downward therefrom is an arm 130 having a roller 1'31 mounted thereon upon two annular roller bearings 132 which in turn :are mounted upon a spindle 133 which projects through the arm 130, and has a pair of nuts .134 on the :outer end thereof, the roller 131 being of :sufiicient length to extend over the surfaces of thecams '98, 101 and .128 respectively as'they are positioned in side to side relation with each other, these cams performing the function of controlling the tilting table during the grinding operation. A spring 135 is mounted upon the table 16 underneath the lower member 21 of the tilting table, which exerts its force upward thereby holding the roller 131 in engagement with the upper surface of one of the three cams at all times, depending upon the particular position of location of the table as to which cam is engaged.

In operation of the device the initial work performed by the machine after the reamer 'blade is manufactured, is the :truing up of the cutting blades in the reamer. This operation is accomplished by placing the reamer stock 36 between the holding members 33 and 34jwith'the pins 35 and 37 projecting into the center holes of the reamer shaft so that the reamer shaft is held between the members 33 and 3 1 freely rotatable upon the pins 35 and 37. The table 16 and the tiltable table are adjusted to the proper height to bring the reamer blades into contact with the grinding Wheel 15 by means of the hand wheel 20. The earn 101, which normally has its upper or bearing surface slightly higher than the upper surface 100 of the cam 98, is moved backwards by means of the hand nut 10% and screw 82, so that the roller 131 contacts only with the upper bearing surface of the cam 101. The table 16, including the pivotally mounted table 21 is thereupon reciprocated by the operator, causing the reamer blades to be carried under the grinding Wheel 15.

The grinding wheel 15 is rotated in a counterclockwise direction, and the table moving from right to left (Figure 2), carries the reamer under the grinding wheel in a direction opposite to that in which the grind ng wheel 15 is rotating. After a very light out, the table is traversed back to the original point so that the cutting portion of the reamer head is away from the surface of the grinding wheel, whereupon the reamer is turned slightly so that another portion of the cutting edge of the reamer blade is brought underneath the surface of the grinding wheeland the operation repeated. A finger, not shown but in common use on machines of this character, causes the reamer to rotate slightly during the grinding operation so that the cutting edge of the reamer blade is presented at the proper angle to the cutting surface of the grinding wheel. After his operation is complete, the grinding portion of the reamer is in the form of a cylinder and the next operation is the relief grinding of the blades at each of their ends.

In order to obtain the proper cut at the forward end of the reamer blade it is, of course, necessary to adjust the reamer stock including the cutting blades, to the proper position with respect to the grinding wheel and the cams. This is accomplished by means of the arm 43 which is lifted to a vertical position, shown in full lines in Figure 1, and the member 45 having the V-shaped opening therein placed over the outer edge of the upper portion of the table 21. This results in a perpendicular position of the arm 13 aligned relation with the center of the bearing 27. The table 16 is shifted if required, so the member 48 and the grinding shaft 13 are aligned, the point 49 being inserted in the center opening of the grinding wheel shaft 13 to better enable the operator to accomplish this alignment. It will be noted (Figure 2), that this alignment has been properly accomplished, the axis of the bearing of the upper table on the lower table is in alignment with the axis of the grinding shaft 13 in a vertical direction.

If the center of the bearing on the table is out of alignment, then the table 16 is moved by suitable adjusting mechanism common to machines of this type, until these centers are in proper alignment with each other. After the table has been properly centered with respect to the grind ing wheel 15, then the gauge member 52 is brought into position with the member 53 placed on top of the reamer blade, one edge of this member being coincident with the point on the member 49 and the axis of the grinding shaft 13. The operator then fixes the point on the reamer blade Where the relief surface terminates, usually the relief surface and will be at 136 on the average reamer blade. After the point 135 on the reamer blade has been fixed, the member 21 is moved until the point 136 on the reamer blade is coincident with the vertical center line of the shaft 13 and bearing 27, this position of the reamer blade being obtained by bringing the point 136 into register with the side of the member 53 which is aligned with these centers.

In order that the length of the relief portion of the cut on the reamer blade may be fixed to suit the particular purpose or the wishes of the user of the reamer blade, the upper portion of the table 21 is adjustable, the adjustment being accomplished by loosening the latch member 32, and by means of a wrench turning the screw 29 into such position as may be desired by the operator, thereby moving the section 21 of the table as may be desired.

As shown in Figure 9, the relief surface and the cutting surface of the blade merge'into each other at the point 136. The point 136 is located on the reamer blade by the operator measuring the distance from the end 137 of the reamer blade and may vary depending upon the clearance desired. The members 33 and 34 are of course placed on the upper section of the table 21 in approximately the proper position to bring the cutting portion of the reamer into the right position with respect to the grinding wheel 15 although in the machine as shown, there is an adjustment of approximately four inches possible in order that reamer blades of different sizes and kinds can be ground upon the machine, and also adjustments may be made in order to provide for different length relief surfaces at each end of the reamer blades.

After the table has been adjusted so the center of the wheel 15, the point 136 and the center of the bearing bracket 23 are aligned vertically, the operator then turns the hand wheel 104 thereby moving the cam 101 until the angular surface 138 at the rear end of this cam is in engagement with the roller 131. The cam 98 has been previously adjusted with respect to the upper grinding surface of the cam 101 so that this surface is slightly below the upper bearing surface of the cam 101, the amount of this difference depending upon the amount of relief which it is desired to obtain at the front end of the reamer blade. This relief varies according to the desire of the user of the reamer, usually ten thousandths of an inch on each side making a total reduction in diameter or" the reamer of twenty thousandths of an inch, although this figure may be greater or less if desired. This relief surface is indicated in Figure 9 at 139, and extends from the outer end of the reamer blade approximately to the point 136 in Figure 9.

A straight surface 140 is formed on the reamer blade extending approximately from the point 136 approximatelyto the point 141. Beginning at point 1 11 the contour of the blade begins to incline towards the rear end of the reamer head. 142. The distance from 14.1 to 142 is immaterial and varies to a very great degree, depending upon the wishes of the user of the reamer. This is the rear portion of the cutting head of the reamer and. is made smaller at the rear end simply to prevent scoring and roughing out of the metal at-the end of the bearing.

The cam 128 is turned at a slight angular position (Figure 3) by turning of the holding casting 107 by the bolt 110 and longitudinal adjustment is efiected by means of the nut 112 which holds the sliding block 11.1 in the opening 59 at the lower side of the casting 55. Ehe roller during the setting of the cams is allowed to remain in contact with the upper surface 100 of the cam 98 and against the sloping surface 138 of the cam 101. Measurement is taken along the reamer blade in order to determine when the relief cut at the rear portion is desired to be taken, and a corresponding measurement is taken from the center of the roller 131 to a point on the upper surface of the cam 101 corresponding to this distance. The cam 128 is thereupon positioned in a longitudinal direction so that its bearing surface and the point of measurement on the upper surface of the cam 101 are coincident with each other so that when the roller 131 reaches the point marked on the upper surface of the cam 101, it will begin to travel upward resulting in tilting the table and causing the grinding wheel to take a deeper cut at this end of the reamer blade than what it has been doing as it travels over the surface of the blade.

Thereafter the operator continues running the reamer blades under the surface of the grinding wheel without any further attention to them other than to see that proper clearance is effected between the grinding wheel and the reamer blades. During this travel the roller 131 is in contact with the upper surface of the cam 101 for a slight distance and as the roller comes in contact with the angular disposed surface 138 on the cam 101, a slight arcuate surface is formed between the surface 140 and 139 on the reamer blade beginning at the point 136 and ending with the surface 140 tangent to the arc.

It will be understood that the dominant feature of the machine is the location of the center of the tilting table in alignment with the point 136 on the reamer blade. In the operation of the machine the table 21 must be parallel with the upper surface of the cam 101 while surface 140 is being ground. The vertical adjustment of this cam is accomplished by means. of the screws 76 and 7'7 which are located on each side of the member 80. A movement of this member results in a corresponding movement of the cam 101 due to the cam 101 resting upon the projecting portion 81 of this member and the guide bar 84. Longitudinal adjustment of this member is secured by the screw 103 and the alignment of the device in a horizontal plane is secured by movement of the lag bolts 93 and 94 which turn the member 60 about its bearing center in the casting 55, thus providing for horizontal adjustment of the cam 101.

The bearing surface of the cam 98 is always positioned below the bearing surface of the cam 101 so that when the roller 131 is in contact with this member the tilting table 21 is in a slight angular position with respect to the horizontal. The reamer is held parallel with the table and therefore is in a slight angular position with respect to a horizontal plane, and as the table moves forward, results in a slight angular cut at the forward end of the reamer blade. This is the portion 139 (Figure 9), extending from the end of the reamer up to a point adjacent 136. Just after the reamer reaches this point, the roller comes in contact with the angular surface of the cam 101 and a slight arcuate shaped surface is formed merging into the straight line surface 140. It

will be understood that when the tilting table is inclined on either side of its center, the grinding wheel will cut the surface of the blade at an angle.

While we have described more or less precisely the details of construction, we do not wish to be understood as limiting ourselves thereto, as we contemplate changes in form and the proportion of pars and the substitution of equivalents as circumstances may suggest or render expedient without departing from the spirit or scope of our invention.

We claim:

.1. A grinding machine, comprising in combination a frame, a reciprocating tiltable table mounted thereon, tool holding means on said table, grinding means, a plurality of cams, and means to co-act with said cams whereby the said table is moved about its center as it is reciprocated, the said cams being individually adjustable.

2. A grinding machine, comprising in combination a frame,.a reciprocating table mounted thereon, a tiltable table mounted on said reciprocating table upon a center substantially in the same vertical plane with the grinding wheel in the normal position of the tiltable table, tool holding means on said tiltable table, an arm connected to said tiltable table, and a plurality of cams adapted to co-act with said arm whereby the said tiltable table is moved about its center as it is reciprocated, the said cams being individually adjustable.

3. A grinding machine, comprising in combination a main frame, a reciprocating table mounted thereon, a tiltable table mounted on said reciprocating table upon a single center substantially in the same vertical plane as the grinding member and in normal position of the tiltable table, tool holding means on said tiltable table, an arm connected to said tiltable table, and a plurality of cams adapted to co-act with said arm whereby the said table is tilted as it is reciprocated, the said cams being adjustable relative to each other, the pivotal mounting of the said table being at one side of the center of the table and opposite the end to which the said arm is attached.

4. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a'pair of cams mounted in said holding block, and a third cam mounted upon said frame member, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

5. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, and a third cam mounted upon said frame nation a main frame, a reciprocating table mounted thereon, a second table pivotally'mount-' ed on said reciprocating table, tool holding means on said second table, an arm at one end of said second table, a cam holding frame secured to said main frame, a holding block rotatably mounted in said cam holding frame, a pair of cams mounted in said holding block, means for adjusting said cams in vertical and longitudial directions, a third cam mounted upon said main frame holding member, and means for vertically adjusting the said third cam, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

7. A grinding machine, comprising in combina tion a main frame, a reciprocating table mounted thereon, a second table pivotally mounted on said reciprocating table, tool holding means on said second table, an arm at one end of said second table, a cam holding frame secured to said main frame, a holding block rotatably mounted in said cam holding frame, a pair of cams mounted in said holding block, means for adjusting said cams in vertical and longitudinal directions, and a third cam mounted upon said main frame holding member, the said third cam being adjustable in a plurality of directions, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

8. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table tiltedly mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, and a third cam mounted upon said frame member, the said tiltable table being composed of upper and lower members, the upper member being relatively movable with respect to the lower member, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

9. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table comprising upper and lower cams pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, a third cam mounted upon said frame member, and means whereby the said upper and lower members are held in fixed relation with each other, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

10. A grinding machine, comprising in combi nation a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm adjustably secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, and a third cam mounted upon said frame member, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

11. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, a third cam mounted upon said frame member, and means whereby the said arm is ad justed with respect to said pivotally mounted table, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

12. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, and a bearing member on said arm, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block at one end thereof, a third cam mounted upon said frame member, and means whereby said bearing member is held in engagement successively with said cams, the said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

13. A grinding machine, comprising in combination a main frame, a reciprocating member mounted thereon, a table pivotally mounted on said reciprocating member, tool holders carried by said table, grinding means, an arm secured to said table, a frame member secured to said main frame, a cam holding block mounted in said frame, a pair of cams mounted in said holding block, a third cam mounted upon said frame member, a bearing member on said arm, and a spring on said reciprocating member adapted to contact with said pivotally mounted table, the

said cams cooperating with the said arm whereby the table is tilted as it reciprocates.

14. A grinding machine, comprising in combination a main frame, a movable table mounted thereon, a pivotally mounted table on said movable table composed of two sections movable relatively to each other, holding means on one of said sections, grinding means, a threaded member secured to one of said table sections, an arm mounted on said threaded member, and a plurality of cams over which said arm is adapted to pass.

15. A grinding machine, comprising in combination a main frame, a grinding wheel mounted thereon, a movable table, a tiltable table mounted on said movable table, a pivotally mounted arm in alignment with the center of the mounting of said tiltable table, and a centering member on said pivotally mounted arm.

16. A grinding machine, comprising in combination a main frame, a grinding wheel mounted thereon, a movable table, a tiltable table mounted 1 on said movable table, a pivotally mounted arm in alignment with the center of the mounting of said tiltable table, means whereby said pivotally mounted arm is held in vertical position, and a centering member on said pivotally mounted arm.

17. A grinding machine, comprising in combination a main frame, a grinding wheel mounted thereon, a movable table, a tiltable table mounted on said movable table, a pivotally mounted arm of said tiltable table, a centering member on said. pivotally mounted arm, and a gauge member on said pivotally mounted arm. 19. A grinding machine, comprising a'mai frame, a grinding wheel thereon, a movable table, a tiltable table on said movable table, tool holding means on said tiltable table, an arm adjustably secured to said tiltable table, a gauge member, a plurality of cams, and means where. by the tiltable table and said arm are adjusted with respect to said cams.

20. A grinding machine, comprising a main frame, a grinding Wheel thereon, a movable table, a tiltable table on said movable table, tool.

grinding wheel, the said members cooperating.

with the said arm to tilt the table as it is reciprocated.

21. A grinding machine, comprising in combi-' nation a main frame, a movable'table, a pivotally mounted table, grinding means, work holding 'i means, an arm, a secondary frame member, a holding block, a pair of cam members mounted thereon, and a third cam member on said secondary frame, each of said cams being adjustable with respect to each other, the said members 'Ic'ooperating with the said arm to tilt the table as it is reciprocated.

22. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding .Imeans, an arm, a secondary frame member, a holding block adjustably mounted on said secondary frame, a cam mounted thereon at one end of said block, a second cam mounted on said block at its other end, and a third cam on said second-' I ary frame, the said cams lying in side to side relation with each other, the said members cooperating with the said arm to tilt the table as it is reciprocated.

23. A grinding machine, comprising in combi- ,;nation a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block adjustably mounted on said secondary frame, a cam mounted thereon at one end fjof said block, a second cam mounted on said block at its other end, means whereby the said second cam is adjusted longitudinally, and a third cam on said secondary frame, the said cams lying in side to side relation with each other, the said fimembers cooperating with the said arm to tilt the table as it is reciprocated.

2a. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding .jmeans, an arm, a secondary frame member, a holding block adjustably mounted on said secondary frame having a head portion thereon, a cam at one end of said holding block, a cam holding member mounted in the head portion '1of said holding member, a second cam, means on said cam holding member for engaging said second cam, and a third cam on said secondary frame,

the said members cooperating with the said arm to tilt the table as it is reciprocated.

25. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block adjustably mounted on said sec- Llondary frame having a head portion thereon, a

cam at one end of said holding block, a cam holding member mounted in the head portion of said holding, member, a second cam having a slot therein, a block in'said' cam holding member extending into said slot, a's'crew adjusting member carried by said. second cam, and in threaded engagement with said block, and a third cam on said secondary frame member, the said members cooperating with the said arm to tilt the table as it is reciprocated. 1

261A grinding machine, comprising in combination a main frame, a movable table, a pivctally mounted table, grinding means, work holding means, an arm, a secondary frame member, a

holding block adjustably mounted on said secondary frame member having a recess in one end thereof and a head portion at the opposite end, a cam mounted in said recess on said holding block, a cam holding member having an extension thereon mounted in the head portion of cam holding member, a second cam having a slot therein on said cam holding member, a block in said cam holding member extending into the slot in said second cam, a screw carried by said second cam in threaded engagement with said block, and a third cam on said secondary frame member in side to side engagement with said second cam, the said members cooperatinng with the said arm to tilt the table as it is reciprocated.

27. A grinding machine, comprising in combination a'main frame, a movable table, a pivotally mounted table, grinding means, Work holding means, an arm, a secondary frame member, a holding block adjustably mounted on said secondary frame member having a recess in one end thereof and a head portion at the opposite end, a cam mounted in said recess on said holding block, a cam holding member having an extension thereon mounted in the head portion of the cam hold-,

ing member, a second cam having a slot therein on said cam holding member, a block in said cam holding member extending into the slot in said second cam; means whereby the said block is adjusted in said cam holding member, a screw carried by said second cam in threaded engagement with said block, and a third cam on said secondary frame member in side to side engagement with said second cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

28. A grinding machine, comprising in combination a main fame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block adjustably mounted on said secondary frame member having a recess in one end thereof and a head portion at the opposite end, a cam mounted in said recess on said holding block, a cam holding member having an extension thereon mounted in the head portion of said cam holding member, a second cam having a slot therein on said cam holding member, a block in said cam holding member extending into the slot in said second cam, wear takeup means carried by said block, a screw carried by said second cam in threaded engagement with said block, and a third cam on said secondary frame member in side to side engagement with said second cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

29. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a bracket on said secondary frame, and a cam mounted on said bracket, the said members cooperating with the said arm to tilt the table as it is reciprocated.

30. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a bracket on said secondary frame, and a cam adjustably mounted on said bracket, the said members cooperating with the said arm to tilt the tables as it is reciprocated.

31. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a bracket on said secondary frame, and a cam mounted on said bracket, the last mentioned cam being mounted in side to side engagement with said second mentioned cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

32. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a right angled bracket having an opening therein on said secondary frame, a cam having a lug portion mounted on said bracket, and a pair of oppositely disposed set screws carried by said bracket and in engagement with the lug portion of said cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

33. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame, having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a bracket, means whereby the said bracket is adjustably mounted on said secondary frame, and a cam adjustably mounted on said bracket in side to side engagement with said second mentioned cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

34. A grinding machine, comprising in combination a main frame, a movable table, a pivotally mounted table, grinding means, work holding means, an arm, a secondary frame member, a holding block mounted on said secondary frame having a recess in one of its sides and a head portion, a cam mounted in said recess, a cam holding block mounted in said head portion, a cam mounted upon said holding block, a bracket, an expansible bushing mounted in said secondary frame, a bolt extending through said expansible bushing and said bracket, and a cam adjustably mounted on said bracket in side to side engagement with said second cam, the said members cooperating with the said arm to tilt the table as it is reciprocated.

LEONARD W. JOHNSON. WILTON F. HOAG. 

